1. Field of the Disclosure
The present disclosure relates to an organic light-emitting display device, and particularly, to designs of adhesive layers of an organic light-emitting display device to control the introduction of cracks in the adhesive layer.
2. Discussion of the Related Art
Organic light-emitting display devices have been noted as being one potential type of next generation display device due to the advantages inherent in their design, for example their high light-emitting efficiency, ease of constructing a large area device, simplified manufacturing processes, their ability to produce blue light, and their inherent physical flexibility. A great deal of research is ongoing on an active matrix light-emitting display devices having an active driving device on each pixel.
An organic light-emitting display device includes an anode, a cathode, and an organic light-emitting unit formed between the anode and the cathode. The organic light-emitting unit emits a white light. The organic light-emitting unit deposits materials for emitting red, green and blue lights on each other so that a synthesized light can appear white.
In an organic light-emitting display device, the anode, the cathode, and the organic light-emitting unit are generally formed on a transparent first substrate such as glass. A second substrate is formed above the first substrate. The first and second substrates are attached to each other by an adhesive layer in an encapsulating manner. Accordingly, foreign materials, such as moisture, are prevented from entering into the organic light-emitting display device.
To attach the first and second substrates to each other, an attachment pressure is applied to the first and second substrates. In existing organic light-emitting display devices, the attachment pressure creates an attachment pressure stress on the substrates that is greater on the corner regions of the organic light-emitting display device than it is on a central region or on the four sides of the organic light-emitting display device. This may cause the adhesive layer to be more concentrated to the corner regions. As a result, cracks may form in the adhesive layer in the corner regions when the adhesive layer is hardened. Moisture may penetrate through the cracks into the organic light-emitting display device. This will negatively affect the quality of the organic light-emitting display device, for example by shortening the lifespan of the device.